There are 12 words that start with 'yeast'.
| yeast | yeasts | yeasty | 
| yeasted | yeastier | yeastily | 
| yeasting | yeastiest | yeastless | 
| yeastlike | yeastiness | yeastinesses | 
Note: These 12 words that start with 'yeast' are found from the USA & Canada version of the tournament Scrabble word list.